Temporomandibular disorder (TMD), or temporomandibular joint disorder, is a broad term that refers to a variety of causes of and symptoms resulting from inflammation of the temporomandibular joint—the joint that connects the lower jaw, or mandible, to the skull. TMD may be caused by a number of factors, including, but not limited to, clenching or grinding of the teeth (during the day or night), trauma, repetitive unconscious jaw movements (or “bruxing”), a lack of symmetry in the relationship (e.g., spacing, etc.) between upper and lower teeth on each side of the head, and a variety of other factors.
There are a number of symptoms associated with TMD. Examples include, without limitation, jaw pain; pain in the temporomandibular joint or in the side of the face; clicking, popping or locking of the temporomandibular joint; sinus pain; ear pain; ringing in the ears, or “tinnitus;” a sense of fullness in the ears; tooth sensitivity; and tension headaches, among others. The symptoms of TMD may complicate daytime activities and interrupt restful sleep.
A number of devices, including a variety of mouth guards, have been developed in efforts to prevent TMD, but with limited effect.